Connecting the Dots: How Local Structure Affects Global Integration in Infants.
By: Palomares, Melanie; Pettet, Mark; Vildavski, Vladimir; Chuan Hou; Norcia, Anthony. Journal of Cognitive Neuroscience. Jul2010, Vol. 22 Issue 7, p1557-1569. 13p. 1 Black and White Photograph, 1 Diagram, 6 Graphs. Abstract: Glass patterns are moirés created from a sparse random-dot field paired with its spatially shifted copy. Because discrimination of these patterns is not based on local features, they have been used extensively to study global integration processes. Here, we investigated whether 4- to 5.5-month-old infants are sensitive to the global structure of Glass patterns by measuring visual-evoked potentials. Although we found strong responses to the appearance of the constituent dots, we found sensitivity to the global structure of the Glass patterns in the infants only over a very limited range of spatial separation. In contrast, we observed robust responses in the infants when we connected the dot pairs of the Glass pattern with lines. Moreover, both infants and adults showed differential responses to exchanges between line patterns portraying different global structures. A control study varying luminance contrast in adults suggests that infant sensitivity to global structure is not primarily limited by reduced element visibility. Together our results suggest that the insensitivity to structure in conventional Glass patterns is due to inefficiencies in extracting the local orientation cues generated by the dot pairs. Once the local orientations are made unambiguous or when the interpolation span is small, infants can integrate these signals over the image. [ABSTRACT FROM AUTHOR] (AN: 49039386)

The role of gaze direction and mutual exclusivity in guiding 24-month-olds' word mappings.
By: Graham, Susan A.; Nilsen, Elizabeth S.; Collins, Sarah; Olineck, Kara. British Journal of Developmental Psychology. Jun2010, Vol. 28 Issue 2, p449-465. 17p. 2 Graphs. Abstract: In these studies, we examined how a default assumption about word meaning, the mutual exclusivity assumption and an intentional cue, gaze direction, interacted to guide 24-month-olds' object-word mappings. In Expt 1, when the experimenter's gaze was consistent with the mutual exclusivity assumption, novel word mappings were facilitated. When the experimenter's eye-gaze was in conflict with the mutual exclusivity cue, children demonstrated a tendency to rely on the mutual exclusivity assumption rather than follow the experimenter's gaze to map the label to the object. In Expt 2, children relied on the experimenter's gaze direction to successfully map both a first label to a novel object and a second label to a familiar object. Moreover, infants mapped second labels to familiar objects to the same degree that they mapped first labels to novel objects. These findings are discussed with regard to children's use of convergent and divergent cues in indirect word mapping contexts. [ABSTRACT FROM AUTHOR] DOI: 10.1348/026151009X424565. (AN: 51535262)

The role of surface discontinuity and shape in 4-month-old infants' object segregation.
By: Kaufman, Jordy; Needham, Amy. Visual Cognition. May2010, Vol. 18 Issue 5, p751-766. 16p. 1 Color Photograph, 1 Diagram, 1 Chart. Abstract: This research examined whether 4-month-old infants use a discontinuity in an object's front surface to visually segregate a display into two separate objects, and whether object shape enables its use. In Experiment 1, infants saw a three-dimensional display composed of two parts with distinctly different shapes. Two groups of infants saw a display in which these two shapes were divided by a visible discontinuity in the front surface (i.e., a boundary between the two objects). One of these groups saw the display move apart at the discontinuity when a gloved hand pulled one object; the second group saw the two objects move together as a single unit. A third group saw a modified version of this display that had no discontinuity present. The results suggested that infants regarded the discontinuity as an indication that the display could be composed of more than one object. In Experiment 2, infants saw the same display, but with a shape that did not highlight the discontinuity. The infants in this study showed no evidence of using the discontinuity. Together, the findings suggest that 4-month-old infants use the surface discontinuity between two objects as an indication that multiple objects could be present in a display, but only when scanning the outer edges of the display leads them to attend to it. [ABSTRACT FROM AUTHOR] DOI: 10.1080/13506280903155638. (AN: 50218782)

Looking at Eye Gaze Processing and Its Neural Correlates in Infancy—Implications for Social Development and Autism Spectrum Disorder.
By: Hoehl, Stefanie; Reid, Vincent M.; Parise, Eugenio; Handl, Andrea; Palumbo, Letizia; Striano, Tricia. Child Development. Jul/Aug2009, Vol. 80 Issue 4, p968-985. 18p. 1 Diagram. Abstract: The importance of eye gaze as a means of communication is indisputable. However, there is debate about whether there is a dedicated neural module, which functions as an eye gaze detector and when infants are able to use eye gaze cues in a referential way. The application of neuroscience methodologies to developmental psychology has provided new insights into early social cognitive development. This review integrates findings on the development of eye gaze processing with research on the neural mechanisms underlying infant and adult social cognition. This research shows how a cognitive neuroscience approach can improve our understanding of social development and autism spectrum disorder. [ABSTRACT FROM AUTHOR] DOI: 10.1111/j.1467-8624.2009.01311.x. (AN: 43221305)

Time Course of Visual Attention in Infant Categorization of Cats Versus Dogs: Evidence for a Head Bias as Revealed Through Eye Tracking.
By: Quinn, Paul C.; Doran, Matthew M.; Reiss, Jason E.; Hoffman, James E. Child Development. Jan/Feb2009, Vol. 80 Issue 1, p151-161. 11p. 1 Color Photograph, 1 Diagram, 2 Charts. Abstract: Previous looking time studies have shown that infants use the heads of cat and dog images to form category representations for these animal classes. The present research used an eye-tracking procedure to determine the time course of attention to the head and whether it reflects a preexisting bias or online learning. Six- to 7-month-olds were familiarized with cats or dogs in upright or inverted orientations and then tested with a novel cat and novel dog in the same orientation. In the upright orientation, infants fixated head over body throughout familiarization; with inversion, no head preference was observed. These findings suggest that infant reliance on the head to categorize cats versus dogs results from a bias that pushes attention to the head. [ABSTRACT FROM AUTHOR] DOI: 10.1111/j.1467-8624.2008.01251.x. (AN: 36386335)

Perceptual identification across the life span: a dissociation of early gains and late losses.
By: Waszak, Florian; Schneider, Werner X.; Shu-Chen Li; Hommel, Bernhard. Psychological Research. Jan2009, Vol. 73 Issue 1, p114-122. 9p. 2 Charts, 2 Graphs. Abstract: The age-correlated gains and losses in visual identification under backward pattern masking were studied in a representative sample of 226 individuals ranging from 6 to 88 years of age. Participants identified masked symbols at leisure under high and low stimulus quality and at varying Stimulus Onset Asynchronies. Performance increased from childhood to early adulthood and then decreased, describing the common inverted U-shaped function. However, measures of general processing speed accounted for the gains in childhood and adolescence but not for losses in older age. This asymmetry between child development and aging is inconsistent with general-factor lifespan theories of cognitive development and suggests that specific mechanisms underlying visual identification during child development and aging are different. [ABSTRACT FROM AUTHOR] DOI: 10.1007/s00426-008-0139-5. (AN: 35996854)

Pubblicazione accademica
Brief Report: Eye Direction Detection Improves with Development in Autism.
By: Webster, Simon; Potter, Douglas D. Journal of Autism & Developmental Disorders. Jul2008, Vol. 38 Issue 6, p1184-1186. 3p. Abstract: Eye direction detection has been claimed to be intact in autism, but the development of this skill has not been investigated. Eleven children with autism and 11 typically developing children performed a demanding face-to-face eye direction detection task. Younger children with autism demonstrated a deficit in this skill, relative to younger control participants. Older children with autism were as accurate as older control participants on this task. In autism, eye direction detection is deficient in late childhood but is typically accurate by adolescence. The implications of this finding for models of social cognitive development in autism are considered. [ABSTRACT FROM AUTHOR] DOI: 10.1007/s10803-008-0539-9. (AN: 32537531)

Reduction in White Matter Connectivity, Revealed by Diffusion Tensor Imaging, May Account for Age-related Changes in Face Perception.
By: Thomas, Cibu; Moya, Linda; Avidan, Galia; Humphreys, Kate; Kwan Jin Jung; Peterson, Mary A.; Behrmann, Marlene. Journal of Cognitive Neuroscience. Feb2008, Vol. 20 Issue 2, p268-284. 17p. 2 Color Photographs, 1 Black and White Photograph, 5 Graphs. Abstract: An age-related decline in face processing, even under conditions in which learning and memory are not implicated, has been well documented, but the mechanism underlying this perceptual alteration remains unknown. Here, we examine whether this behavioral change may be accounted for by a reduction in white matter connectivity with age. To this end, we acquired diffusion tensor imaging data from 28 individuals aged 18 to 86 years and quantified the number of fibers, voxels, and fractional anisotropy of the two major tracts that pass through the fusiform gyrus, the pre-eminent face processing region in the ventral temporal cortex. We also measured the ability of a subset of these individuals to make fine-grained discriminations between pairs of faces and between pairs of cars. There was a significant reduction in the structural integrity of the inferior fronto-occipital fasciculus (IFOF) in the right hemisphere as a function of age on all dependent measures and there were also some changes in the left hemisphere, albeit to a lesser extent. There was also a clear age-related decrement in accuracy of perceptual discrimination, especially for more challenging perceptual discriminations, and this held to a greater degree for faces than for cars. Of greatest relevance, there was a robust association between the reduction of IFOF integrity in the right hemisphere and the decline in face perception, suggesting that the alteration in structural connectivity between the right ventral temporal and frontal cortices may account for the age-related difficulties in face processing. [ABSTRACT FROM AUTHOR] (AN: 28452175)

Working memory and Down syndrome.
By: Baddeley, A.; Jarrold, C. Journal of Intellectual Disability Research. Dec2007, Vol. 51 Issue 12, p925-931. 7p. Abstract: A brief account is given of the evolution of the concept of working memory from a unitary store into a multicomponent system. Four components are distinguished, the phonological loop which is responsible for maintaining speech-based information, the visuospatial sketchpad performing a similar function for visual information, the central executive which acts as an attentional control system, and finally a new component, the episodic buffer. The buffer comprises a temporary multidimensional store which is assumed to form an interface between the various subsystems of working memory, long-term memory, and perception. The operation of the model is then illustrated through an account of a research programme concerned with the analysis of working memory in Down syndrome. [ABSTRACT FROM AUTHOR] DOI: 10.1111/j.1365-2788.2007.00979.x. (AN: 27373480)

Individual Differences and the Development of Joint Attention in Infancy.
By: Mundy, Peter; Block, Jessica; Delgado, Christine; Pomares, Yuly; Van Hecke, Amy Vaughan; Parlade, Meaghan Venezia. Child Development. May/Jun2007, Vol. 78 Issue 3, p938-954. 17p. 1 Black and White Photograph, 6 Charts, 1 Graph. Abstract: This study examined the development of joint attention in 95 infants assessed between 9 and 18 months of age. Infants displayed significant test–retest reliability on measures of following gaze and gestures (responding to joint attention, RJA) and in their use of eye contact to establish social attention coordination (initiating joint attention, IJA). Infants displayed a linear, increasing pattern of age-related growth on most joint attention measures. However, IJA was characterized by a significant cubic developmental pattern. Infants with different rates of cognitive development exhibited different frequencies of joint attention acts at each age, but did not exhibit different age-related patterns of development. Finally, 12-month RJA and 18-month IJA predicted 24-month language after controlling for general aspects of cognitive development. [ABSTRACT FROM AUTHOR] DOI: 10.1111/j.1467-8624.2007.01042.x. (AN: 25075041)